1. Field
Example embodiments relate to an indoor unit to supply power to a load device, a method thereof and an air conditioning system having the same.
2. Description of the Related Art
In general, an air conditioner is an apparatus that is used to cool or heat a room. In the air conditioner, a refrigerant is circulated between an indoor unit and an outdoor unit, and a cooling or heating operation is performed based on the principle that the refrigerant absorbs ambient heat when evaporated from a liquefied state and discharges the heat when liquefied.
An air conditioner generally has one outdoor unit and one indoor unit connected to the outdoor unit. Recently, users have increasingly demanded a system air conditioner in which a plurality of indoor units with various shapes and volumes are connected to one or more outdoor units to perform a cooling or heating operation with respect to a place having a number of divided spaces, such as a school, company or hospital.
For example, such a system air conditioner may include one outdoor unit and a plurality of indoor units, and a direct current (DC) power line, a communication line, etc. may be connected between the outdoor unit and each indoor unit to enable communication between the outdoor unit and each indoor unit.
On the other hand, in a system air conditioner, a plurality of indoor units may often be controlled by a wired remote controller differently from those in a household air conditioner because a wireless remote controller may be lost. In the system air conditioner, the wired remote controller may be used in common for the indoor units and connected to the indoor units using a 2-line scheme. The 2-line scheme is a technique that links a communication signal to a power supply line and transmits power and the communication signal together through the power supply line (the power supply line that is linked with the communication signal and transmits the communication signal will hereinafter be referred to as a “power/communication line”). The indoor units may supply powers to the wired remote controller through the power/communication line. If the indoor units simultaneously supply the powers to the power/communication line, a short circuit may occur, resulting in a fault.